Releasable lock for guide bushings



Jan. 2, 1951 J c, -11 2,536,424

RELEASABLE LOCK FOR GUIDE BUSHINGS Filed March 21. 1945 Eigi. 0

15204972507": John (I. C'urZia.

MIF'MAM aw y.

Patented Jan. 2, 1951 RELEASABLE LOOK FOR GUIDE BUSHINGS John 0. Curtis, Claremont, N. H., assignor to Joy Manufacturing Company, a corporation of Pennsylvania 4 Application March 21, 1945, Serial No. 583,868

UNITED STATES PATENT OFFICE 3 Claims.

intervals.

against rotative movement.

invention may assume in practice.

In this drawing:

ing implement. The front piston extension extools of other types.

tends through a bore in the front cylinder head The hammer rock drill comprises a motor or buffer ring and some diificulty has been excylinder 5 having a bore 2 in which a hammer pisperienced in the adequate guiding of the piston ton 3 is reciprocable. The hammer piston has a extension. To overcome this difficulty, replacehead 4 fitting the cylinder bore and a reduced able bearing sleeves or bushings have been sup- 1.5 elongated front extension or striking bar 5 for ported within the front buffer ring for providdelivering impact blows to the shank of a working a bearing for the piston extension, and such ing implement 6, herein a conventional rock drill bushings become worn and must be replaced at steel.

It is therefore desirable to provide cylinder is a chuck housing 1 containing a chuck means for securing the bushing in position in 8 for receiving and supporting the drill steel the front head and such securing means must be shank. The piston extension 5 extends through a readily releasable to enable easy replacement of bore in a front cylinder head 9, and pressed in the bushing. It is also desirable to provide rethe front head bore is a bearing sleeve or guide leasable securing means whereby the bushing bushing l0 providing a bearing surface for the may be readily locked in its guiding position and piston extension for guiding the latter during held not only against axial displacement but also reciprocation of the piston.

has a rearwardly located, inwardlyjdirected an-" It is accordingly an object of the present innular flange H providing a forwardly facing vention to provide improved means for securing shoulder l2 against which the rear end of the the guide bushing for the front piston extension bushing abuts, and the flange II is cut away or or striking bar of a hammer rock drill against notched at It so as to enable, when the drill is both axial displacement and rotative movement. dismantled, the pla Of a Suitable instrument Another object is to provide improved means for against the rear end of the bushing to permit guiding the front extension of the reciprocating driving out of the bushing from the head bore. hammer piston of a fluid operated tool. Still an The forward portion of the bushing is externally other object is to provide improved releasable reduced at M and has a notch at i5 in the remeans for locking the guide bushing in position duced portion. The front head 9 is recessed at in the front cylinder head or buffer ring, such I6 and internally annula ly grooved at W means enabling easy locking of the bushing in the bushing is driven in position in the front head guiding position and permitting ready release of bore, a locking ring or spring lock I8 is placed the bushing for replacement purposes. These and about the reduced front end of the bushing and other objects and advantages of the invention snapped into position in the groove H with a bent will, however, hereinafter more fully appear. end portion l9 received in the front head recess In the accompanying drawing there is shown It in the manner shown. An end 20 of the spring for purposes of illustration one form which the lock is inserted in the notch l5 in the bushing. When the drill is assembled, the locking ring l8 serves to hold the guide bushing against forward Fig. 1 is a fragmentary view in central longiaxial displacement from the front head bore, tudinal section through a hammer rock drill in and the end 20 received in the bushing notch which an illustrative embodiment of the inven- I5 serves to hold the bushing against rotative tion is incorporated.

Fig. 2 is a cross-sectional view taken substantially on line 2-2 of Fig. 1.

Fig. 3 is a detail view of the improved locking element.

Fig. 4 is a perspective view of the replaceable bearing sleeve or guide bushing. 1

Fig. 5 is an enlarged fragmentary sectional view taken on the plane of Fig. 1, showing structural details of the invention.

In this illustrative construction there is shown fluid operated tool, herein a hammer rock drill, in which the invention is incorporated. It will be evident that the invention may be associated with Attached to the front end of the motor The front head 9 movement in the head bore. When it is desired to replace the bushing, as in the event of wear, the drill may be dismantled and the locking ring pried or otherwise released from its locking position by springing the ring out of the groove I'I guide bushing may be readily locked in guiding position in the front motor head, and mayalso be readily released when desired. The improved bushing lock is simple and inexpensive in .con-

struction and is extremely compact, and 'due to its design may be associated with a standard type of hammer rock drill with a minimum of change.

Other advantages of the invention will be clearly V apparent to those skilled in the art.

While there is in this application specifically described one form which the invention may .a-ssume in practice, it will be understood that this form of the same is shown for purposes of illustration and that the invention may be modified and embodied in various other forms Without departing from its spirit or the scope of the :appended claims.

What I claim as'new and desire to secure by Letters Patent is:

1. In combination, a member having a bore forming an annular shoulder at one end and having an annular groove in its walls near its opposite end providing a shoulder opposed to said annular shoulder and a recess with which said groove communicates, a guide bushing received in, said bore and. adapted to guide a member to be guided, said bushing atone end engaging said annular shoulder, and a releasable loci: for re taming said "bushing in said bore with said one end thereof against said annular shoulder including an expansible split spring ring surrounding said bushing and seated in said groove, said ring-engaging a surface on said bushing opposed to said groove-shoulder and having a bent portion atone end received in said recess andat said end interlocked with said 'bushing to hold the lat-- terragainst substantial rotation in said bore, said' ring being contractible to efiiect release thereof from said groove to permit axial release or" said bushing from said bore, and said bent portion moving outwardly from said recess during such axial release of said bushing.

,2, hi combination, a member. having a bore forming an annular shoulder at one end and hav ing an annular groove in its walls near its opposite end providing a shoulder opposed to-said annular shoulder and a recess with which said groove communicates, a guide bushing received in said bore and adapted to guide a member to be guided, said bushing at one end engaging said annular shoulder and having a notch at its opposite end, and a releasable lock for retaining said bushing in said bore with said one end against said annular shoulder including an expansible split spring ring surrounding said bushing and seated in said groove and engaging a surface on said bushing opposed to said grooveshoulder, said ring having a bent portion at one end received in said recess and said end received in said notch to hold the bushing against substantial rotation in said bore, said ring being contraotible to effect'release thereof from said groove to permit axial release of said bushing from said "bore, and said bent portion moving outwardly from said recess during such axial release of said bushing.

3. In combination, a member having a bore formed with an annular shoulder at one end and having an annular groove in its walls near its opposite end providing a shoulder opposed to said annular shoulder, a guide bushing received in said bore and adapted to guide a member to be guided, said bushing at one end engagingsaid annular shoulder and having a reduced portion at its opposite end providing a shoulder opposed to said groove-shoulder, and a releascontractible to eiiect release thereof from said groove to permit axial release of said bushing from said bore, said ring moving out of inter-,-

looking relation with said member during such axial release of said bushing.

' JOHN C. CURTIS.

REFERENCES CITED The followingreferences. are of record in the file of this patent:

UNITED STATES PATENTS Number I Name Date 1,143,534 Gilman June 15, 1915 1,464,386. Ingram .Aug, '7, 1923 1,541,410 Cowley June 9, 1925v 1,809,309 Olander June 9, 1931 Certificate of Correction Patent No. 2,536,424 January 2, 1951 JOHN G. CURTIS It is hereby certified that error appears in the printed specification of the above numbered patent requiring correction as follows:

Column 4:, list of references cited, under the heading UNITED STATES PATENTS add the following:

Be. 15,187 Reynolds Sept. 6, 1.921 839,281 Fluke Dec. 25, 1.906 1,909,230 Smith May 16, 1.933 2,025,848 OoZZz's Dec. 31, 1935 2,051,704 H arm's Aug. 18, 1936 2,380,947 Brozelc Aug. 14, 1945 and that the said Letters Patent should be read as corrected above, so that the same may conform to the record of the case in the Patent Oflice.

Signed and sealed this 17th day of July, A. D. 1951.

[SEAL] ERNEST F. KLINGE,

Assistant Gammz'ssz'oner of Patents. 

